Halo-substitution of mixtures containing saturated organic compounds



' captan which in itself is an Patented May 26, 1942 HALO-SUBSTITUTION F MIXTURES CO N- TAINING SATURATED ORGANIC COM- POUNDS William E. Vaughan and Frederick F. Rust,- Berkeley, Calif., assignors to Shell Development Company, San Francisco, Calif.,

of Delaware No Drawing.

12 Claims.

The present invention relates to halogenation,

and more particularly pertains to an improved and economical process for halogenating, via

' substitution, a saturated organic compound of the the above-defined organic compounds and oxygen or an oxygen-containing gas, such as air.

The halides of saturated aliphatic and cycloaliphatic hydrocarbons find numerous uses bothas intermediates and as final products. For example, ethyl chloride and ethyl bromide are employed for the preparation of tetraethyl lead.

Ethyl chloride is also the primary material for making ethyl cellulose, as well as of ethyl merintermediate in the preparation of sulfonal, a known soporific. Also, ethyl chloride is used as a refrigerant and as a local freezing anesthetic for minor operations. The other saturate aliphatic and alicyclic halides are also highly useful and valuable products. For instance, cyclopentyl chloride, itself a good solvent, is an intermediary for the preparation of cyclopentanol, which is employed in lacquer manufacture.

It is known that saturated aliphatic and/or cycloaliphatic hydrocarbons, as well asv their products of partial halogenation, may be halogenated or further halogenated, by reacting them with a halogen, such as chlorine, bromine or iodine, at an elevated temperature which induces a substitution reaction" in which a halogen atom is substituted for a hydrogen atom at- -tached to a carbon atom of the hydrocarbon molecule. It is also known that such halo-subs' itution reactions between a halogen and a saturated hydrocarbon of the above-defined and hereinbelow more fully described class may be efiected efiiciently by subjecting the mixture to elevated temperatures which favor the halo-substitution reaction, these temperatures, however,

being below those at which substantial degrada tion and/or decomposition of the reactants and/or reaction products occurs.

It has been previously found that the presence of olefinic hydrocarbons above ethylene inhibits the high temperature halo-substitution of aliphatic and/or alicyclic hydrocarbons so that, to obtain such halo-substitution of these. aliphatic and/or alicyclic hydrocarbons, it is necessary to was also disclosed in the aforementioned copending application that this inhibiting effect of a corporation Application February 13, 1940, Serial No. 318,716

eflect the reaction at temperatures which areconsiderably above those necessary for the halosubstitution of these hydrocarbons when in the absence of such olefinic compounds. This is disclosed in our co-pending application Serial No. 291,365, filed Aug. 22, 1939, now Patent No. 2,246,082, wherein it is shown that olefins of a secondary character, having three or ,more carbon atoms per molecule, when brought in contact with a halogen at an elevated temperature, for example, above 225 0., not only react with the halogen to produce unsaturated halides, but also retard or even inhibit the halogenation, via substitution, of the saturated aliphatic and/or alicyclic hydrocarbons which may be originally present in the hydrocarbon mixture subjected to the high temperature halogenation reaction. It

the secondary olefins above ethylene is believed to .be due to the interaction of these olefins with the hydrocarbon free radicals which are formed as a consequence of the removal of a hydrogen atom from the saturated hydrocarbon molecule during the reaction. The reaction of the olefins with these free radicals forms relatively larger radicals which, by reason of orientation requirements for successful collision, react less rapidly with the halogen than do the relatively smaller radicals. This, in turn, is believed to retard or even completely inhibit the further continuation of the chain mechanism, thereby retarding and/or inhibiting the halogenation of the saturated organic compounds.

The inhibiting efiect of the various-olefins having three or more carbon atoms per molecule on halo-substitution reactions, however, varies with the nature of the olefin. For instance it was found that propylene is the most effective inhibitor. eifect of ethylene on the high temperature halosubstitution of saturated aliphatic and/or alicyclic hydrocarbons is substantially nil so that in the. presence of this olefin, the saturated compounds may be readily subjected to eflicient and economical conversion into their products of halo-substitution. The other olefins, although they are less effective than propylene as inhibitors for the halo-substitution of saturated organic compounds, nevertheless may all be con- On the other hand, the inhibiting I The inhibitory eiIectof oxygen on the halosubstitution of saturated organic compounds is well known. Also, in our co-pending application Serial No. 293,486, filed September 5, 1939, now Patent No. 2,278,527, it was disclosed that oxygen, or an oxygen-containing gas, such as air, at least when present in small and definite quantities or percentages, promotes the halo-substitution of unsaturated organic compounds of primary and secondary character, so that the halo substitution thereof may be effected at temperatures below those which may be necessary for the halo-substitution of these unsaturated organic compounds in the absence of such oxygen. Furthermore, it has been previously discovered that oxygen apparently inhits the halo-addition reaction so that the resultant product, although obtained at temperatures at which normally considerable halo-addition products would be present, are substantially free from such saturated halides as may be produced by halo-addition.

In view of the above knowledge it would normally be expected that the presence of oxygen during the high temperature halogenation of a mixture of saturated and unsaturated aliphatic and/or alicyclic organic compounds, such as ali phatic and/or alicyclic hydrocarbons, would catalyze the halo-substitution of the unsaturated hydrocarbons, while inhibiting the halo-substitution of the saturated compounds. On the contrary, as will be more fully shown in the following description and in the examples, the halo-substitutio'n of unsaturated organic compounds, such as olefins and/or cyclo-olefins, will be retarded or even substantially inhibited if such reaction .is attempted to be efiected in the presence of oxygen and of saturated aliphatic and/o1- alicyclic compounds of the described class. Ithas been discovered, however, contrary to all expectations,-that the halo-substitution of saturated aliphatic and/or alicyclic organic compounds, which halo-substitution has been suppressed or inhibited by the presence of oxygen, may be promoted or catalyzed by the addition to the reaction mixture of unsaturated organic compounds, such as olefins and/or cyclo-olefins. It has been further discovered that the halogenation of saturated aliphatic and/or alicyclic organic compounds, the halo-substitution of which has been inhibited by the presence of oxygen, is proportional to some function of the concentration of the unsaturated hydrocarbons in the oxygen-containing mixture of saturated and unsaturated organic compounds subjected to high temperature halogenation. In fact, when the unsaturates are present in excess of the halogen, the reaction rate between the saturates and the halogenis proportional to the square of the unsaturate concentration, While, in the case where the halogen' is in excess of the unsaturates, this reaction rate is directly. proportional to the first power of the molal concentration of the unsaturates, such as olefins, in the reaction mixture.

It is to be noted that the saturated aliphatic and/or alicyclic compounds of the above-defined and hereinbelow more fully described class may be halogenated without the addition of the unsaturated compounds even though oxygen is present in the reaction mixture. This may be accomplished by raising the operating temperature. In other words, the presence of oxygen merely elevates the onset temperature, 1. e. the temperature at which the halo-substitution reaction vinyl chlorides, also possess the aforementioned inhibiting power.

is initiated. For example, if a saturated aliphatic hydrocarbon may be effectively halogenated at a given temperature, the addition to such halogen-hydrocarbon mixture of a specified percentage of oxygen or of an oxygen-containing gas will retard or even totally inhibit the reaction if attempted at the same temperature. However, by raising such temperature, it is possible to offset the inhibiting efiect of the oxygen and to effect the halo-substitution reaction. Since some saturated aliphatic and/or alicyclic hydrocarbons, particularly the lower boiiing fractions, such as those obtained during petroleum refining operations, frequently contain oxygen or air, and since the removal of such oxygen, for instance, by treatment with chromous chloride or sulphate solutions, is frequently undesirable because of cost, the halogenation of such oxygen-containing saturated compounds would necessitate the use of excessively high temperatures, which in turn would raise the cost of manufacture of the organic halides. Also, the high temperatures will cause excessive decomposition of the reactants, thus decreasing the yield of the desired halides. These defects are all avoided by efl'ecting the halo-substitution in accordance with the process of the present invention.

The invention may therefore be broadly stated to reside in a process for halogenating saturated aliphatic and/or alicyclic hydrocarbons, 'as well as their products of partial halogenation, the halogenation of which compounds has been in hibited or suppressed by the presence of oxygen, which comprises efiecting the halogenation of such compounds in the presence of oxygen and of unsaturated hydrocarbons, at elevated temperatures which are, however, below those which are necessary for the halogenation of the saturated compounds in the presence of oxygen, but in the absence of the unsaturated hydrocarbons.

The invention further resides in the process for the halo-substitution of saturated organic compounds of the class of saturated aliphatic and alicyclic hydrocarbons and of the products of their partial halogenation, which compounds are in admixture with oxygen or an oxygen-containing gas, such as air, thisprocess comprising the steps of adding unsaturated aliphatic or alicyclic hydrocarbons, such as olefins or cyclo- 0lefins,'to the oxygen-containing saturated organic compound, and subjecting the mixture thus produced in a vapor state to the action of a halogen, e.. g. chlorine, bromine and/or iodine, at an elevated temperature below that at which substantial decomposition of the carbon structure occurs. As stated above, the presence of the unsaturated compounds, in effect, ofisets the inhibitory eifect of the oxygen so that the halosubstitution of the saturated compounds may be realized at considerably lower temperatures as compared to those which would be necessaryfor the halo-substitution of mixtures containing saturated organic compounds and oxygen, but which 'do not contain any unsaturated compound, such as olefins and/or cycle-olefins. Depending on the saturated compound to be halogenated and on the oxygen concentration, the onset tempera- ,ture, i. e. the temperature at which halo-substigenation." In view of this, the operating temperature will depend on a number of variables,

such as the specific saturated organic compound I to be halo-substituted. the unsaturated hydrocarbon employed, its concentration, concentration of oxygen in the mixture; degree of halo-sum stitution desired, reaction residence time, etc.

It may be generally-stated. however, that such. 1

operating temperature will be above about 250 C., and preferably considerably higher in order to obtain high yields of the desired products of desired products of halo-substitution. The optimum operating temperature will also vary with the time during which the reactants are subjected to the halogenation reaction temperatures. Generally, with longer residence periods, lower temperatures may be used.

The invention may be executed in a batch, intermittent or continuous manner. Preferably, the saturated organic compound containing oxygen or an oxygen-containing gas, as well as the halogen and the unsaturated hydrocarbon which is to be added to the mixture to1promote or catalyze the halo-substitution of the saturated compound or compounds, should be separately preheated substantially to the optimum or desired temperature, and then commingled at such temperature substantially at or near the inlet to the reaction chamber. Such an operation prevents or inhibits undesirable side-reactions which may occur if the reactants are brought together at lower temperatures or in a liquid phase. In the alternative, the saturated organic compound contaminated with air or oxygen may be commingled with the olefins or the like, prior to the preheating, after which this preheated mixture is commingled with the halogen which may or may not be preheated to the desired or optimum temperature which promotes or causesthe desired halo-substitution.

As representative compounds which may be halogenated according to the present invention, reference may be made to alkyl hydrocarbons, as ethane, propane, butanes, pentanes and their higher homologues, alicyclic or polymethylene hydrocarbons such as cyclopropane, methyl cyclopropane, cyclobutane, cyclopentane, etc., as well as the partially halogenated derivatives of the saturated aliphatic and cyclo-aliphatic hydrocarbons, such as ethyl chloride, n-propyl bromide, n-propyl chloride, secondary butyl genation of which has been inhibited by the presence of oxygen), reference may be made to aliphatic and alicyclic oleflns, such as ethylene, propylene, butene-l, butene-2, cyclo-butene, cyclopentene, and the like and their homologues and analogues, as well as to halo-substituted unsaturated aliphatic and cyclo-aliphatic hydrocarbons, as vinyl chloride, vinyl bromide, allyl chloride, cyclopentenyl chloride and the like, their homologues and analogues.

The invention is illustrated by the following examples which are presented herein for thepurpose of showing the advantages derived from operation in accordance with the process 01' the present invention, as well as for the purpose'of indicating'the results obtained thereby. These examples, however, are not to be considered as limiting the invention in any sense.

Example I stitution of chlorine into the ethylene.

Example II This run was effected in the same reaction chamber and under the same operating condichloride, dichlorbutane, monochlorcyclopentane,

and the like and their homologues and analogues. The saturated aliphatic or alicyclic compounds may also be linked to one or more aromatic radicals. For example, compounds which may be treated'according to the .present invention include phenyl 'alkyl hydrocarbons. Also, saturated aliphatic and/or alicyclic acids, ketones, alcohols, esters, etc., fall within the class of compounds which may be employed as the primary material and which maybe halogenated via substitution in accordance with the process of the present invention.

As to the unsaturated organic compounds which are suitable as substances which promote the high temperature halo-substitution of the above-described saturated .compounds (the halotions as those employed in the above example, the only difference between the two runs being that in the present run ethane was added in a quantity equal to 50 c.c./min. and that only 175 c.c./min. of the nitrogen were employed. This substitution of ethane for a part of the diluent markedly lowered the reaction rate, only about 15% of the chlorine being found to have reacted. Also, an analysis of the reaction product showed that it predominated in ethyl chloride.

Example III A gaseous mixture of ethane, chlorine and nitrogen, in a volumetric ratio of 2:1:45, was passed at a total rate of about 300 c.c./min., together with oxygen in a quantity of about 1.5 c.c. /min. to the same reaction chamber as that employed above. maintainedat 327 C. An analysis of the eiliuent gases failed to show any reaction between the ethane and the chlorine.

A comparison of the results described in the above examples clearly shows that an olefin chlor-substitution reaction catalyzed by the presence of small quantities of oxygen, is, in turn, inhibited by the addition of a saturated aliphatic hydrocarbon, it being noted that when such saturated hydrocarbon is added there is substantially no dolor-substitution into the olefin. Furthermore. the examples show the ad-. vantages obtained when an olefin is added to an oxygen-containing paradise-chlorine mixture. 'I'hus, whereas the oxygen inhibited the chlor- .substitution into the ethane, the addition of 1 ethylene to such oxygen-containing mixture The reaction temperature was Example IV A mixture of ethane, ethylene, chlorine, oxygen and carbon dioxide (diluent) was conveyed through a reaction chamber at a rate of about 100 c.c./min. of ethane, 50 c.c.lmin. of chlorine, 45 c.c./min. of CO2 and 1.5 c.c.lmin. of oxygen. The reaction chamber, which consisted of a Pyrex glass tube 45 cmtlong and 1.35 cm. internal diameter, was maintained at a temperature. of 336 C.- The reactants, prior to commingling, were separately preheated to the reaction temperature, and were then mixed at such temperature substantially at the entrance to the reaction zone. The reaction was quite vigorous, there being considerable carbon formation. An analysis of the effluent reaction product showed the. following distribution:

Trichlor-ethanes 12 This-test clearly shows that the reaction is primarily one of chlor-substitution into th ethane.

Example V stitution rising to about-72% at a reaction temperature of 404 0. Despite the fact that the chlorination under these conditions depends upon the presence of the olefin, as this is shown by the fact that when the ethylene in the above tests, and the percent chlorine which reacted by substitution are shown in the following table:

Rate of introduction, in c. cJmin. Percent chlorine substituted Ethylene Nitrogen Example VII A series of tests were effected with-constant throughputs of chlorine, ethane and oxygen.

7 The rate of introduction of ethylene and nitrogen was varied as in the previous example.

However, in the present series, the ethylene was always maintained in excess of the chlorine employed. The reactions were effected at a temperature of about 327 C., the reactants being employed in the following quantities: 12.5 c. c./

mixture was replaced by a diluent, such as carbon dioxide, and when the reaction was effected at 374 C., only about 4% of the chlorine reacted (as compared to the 60% conversion obtained in the presence of the ethylene), an analysis of the reaction products shows that chlor-substitution into the ethane, and therefore the formation of ethyl chloride, is the principal reaction. This clearly indicates that the olefin catalyzes the paraflin chlor-substitution reaction while the presence of such saturated hydrocarbon inhibits the chlorination of the unsaturates present in the reacting mixture.

Example VI A series of chlorination tests wereconducted with a mixture containing ethane, ethylene, chlorine, oxygen, and nitrogen as diluent. In all of these tests the rates of throughput of chlorine, or ethane and of oxygen were maintained constant, these substances being conveyed through the reactor in the following quantities: c. c./min.

of chlorine, 50 c. c./min. of ethane and 1.5 c. c./ min. of oxygen. The total rate of introduction of ethylene and nitrogen was also maintained constant at 195 c, c./min. However, the respective quantities of these two substances were varied from test to test. All of the reactions were efiected in the above described Pyrex glass tube maintained at about 327 C. The rates of ethylene and nitrogen employed in each of the min. of chlorine, 50 c. c./min, of ethane, 1.5 c. c./min. of oxygen and 230 c. c./min. of ethylene and nitrogen. The specific throughputsof these last mentioned two substances, as well as the effect of varying the quantity of ethylene employed on the degree of chlor-substitution of the ethane are given in the following table:

Rate of jntroduction, in c. c./ Percent i min. chlorine reacting via substitution Ethylene Nitrogen 50 180 5.6 11.2 80 224 s 200 30y 42.4 2&0 0 56.0

As in the case of the products of reaction obtained in the previous example, the principal reaction product found'in the reaction products was ethyl chloride, thus showing that the presence of the ethy ene promotes or catalyzes the halo-substitution of the saturated hydrocarbon,

i. e. ethane.

An analysis of the data and results described 1 1n Examples'v and VI shows that other conditions being equal, an increase in the quantity of olefin added to an oxygen-containing parafiln-.

halogen mixture, increases the yield of products of halo-substitution of the paramns. Also, as long as the olefin is present in a quantity not in excess of that of the halogen, this increase in the degree of halo-substitution is only directly proportional to the increase in the olefin content, whereas, when the olefin is present in quantitles in excess of that of the halogen, the degree.

or percent of chlor-substitution of the paraflins is proportional to the square of the mol. concentration of the olefins in the oxygen-containing mixture of saturated and unsaturated organic'compoun'ds subjected to the high temperature' halogenation in accordance with the process of the present invention. 7

The carbon dioxide and the nitrogen were em ployed in the above examples merely forthe purpose-of diluting the hydrocarbon-chlorine mixert diluents, such'as helium, may be employed in connection with or in lieu of the aforementioned diluents. i

The reaction may be efiected at any suitable pressure. Generally, the halo-substitution reaction according to the present invention may be efiected at. atmospheric pressures. However,

somewhat higher or lower pressures may also be employed.

Although the invention has been described with particular reference to the chlorination of ethane in the presence of oxygen and ethylene, it is to be understood that other saturated organic compounds and their partially halogenated-derivatives (containing oxygen admixed therewith) may be halogenated, i. e. subjected to chlorination, bromination and/or iodination, via substi-. tution, in accordance with the process or this invention by the addition to such mixture to be halogenated of an unsaturated organic compound, such as an olefin or cycle-olefin.

Generally it is preferable to employ an amount of halogen not in excess of that theoretically required to react with all of the saturated aliphatic and/pr alicyclic organic compound to be halogenated. The presence of an excess of halogen is usually to be avoided since such excess is conducive to the formation of undesirable highly halogenated products. On the other hand, the maintenance of an excess of the halogenatable compound prevents such side reactions and is therefore desirable.

The reaction or residence time will vary depending on the specific organic compound to be subjected to treatment, the molal concentration and character of the olefin and/or'cyclo-olefin added, as well as on the oxygen and halogenconcentrations and the temperature employed.

We claim as our invention:

1. In a process for the production of .ethyl chloride from ethane which is contaminated by the presence of oxygen, the steps of adding ethylene to the oxygen-contaminated ethane and subjecting the mixture to the action of chlorine in the vapor state at a temperature of between about 250 and 425 0., thereby efiecting the chlor-substitution into the ethane to the substantial exclusion of reactions between the chlorine and ethylene, and separating the ethyl chloride thus produced from the reaction mixture.

2. The process according to claim 1 wherein the reactants are maintained at the reaction temperature for a period of timev insuflicient to effect the decomposition of the carbon structures of the organic reactants and of the reaction product.

3. In a process for the production of ethyl chloride from ethane which is contaminated by the presence of oxygen, the steps of adding ethylene to the oxygen-contaminated ethane, subjecting said mixture to the action of chlorine in the vapor state at a temperature of' above 250 C. and for a period of time insufficient to effect the decomposition of the carbon structure of the organic reactants and reaction product,

thereby efiecting the chlor-substitution into the ethane to the substantial exclusion of reactions between the chlorine and the ethylene, and separately recovering the ethyl chloride from the reaction mixture.

4. In a process for the production of ethyl halides from ethane which is contaminated by the presence or oxygen, the' steps of adding, to such oxygen-ethane mixture, an unsaturated organic compound'selected from the group consisting of aliphatic and alicyclic olefins and of their products of halo-substitution, subjecting the mixture thus obtained in the vapor state to the action of ahalogen selected from the group consisting of chlorine, bromine and iodine at a temperature of about 250 C. but below that at which substantial decomposition of the carbon structure of the organic reactants and of the reaction product occurs, thereby effecting the halo-substitution of the ethane to the substantial exclusion of'reactions between the halogen and the added unsaturated organic compound, and separately recovering the ethyl halide from the resulting reaction mixture. I

5. The process according to claim 4, wherein the unsaturated organic compound added to the oxygen-contaminated ethane is an olefin.

6. The process according to claim 4 wherein ethylene is addedto the oxygen-contaminated ethane.

7. In a process for the halo-substitution of saturated aliphatic hydrocarbons which'are contaminated by the presence of oxygen, the steps of adding to said oxygen-contaminatedsaturated aliphatic hydrocarbon an unsaturated organic compound selected from the group consisting of aliphatic and alicyclic olefins, and of their products of halo-substitution, subjecting the mixture thus produced, in the vapor state, to the action of a halogen selected from the group consisting of chlorine, bromine and iodine at a temperature of above 250 C. but below that at which substantial decomposition of the organic reactants and of reaction products occurs, thereby effecting the halo-substitution of the saturated aliphatic hydrocarbons to the substantial exand alicyclic olefins and of their products of halo-substitution, subjecting said mixture to the action of a halogen selected from the group consisting of chlorine, bromine and iodine in a vapor state at a temperature of above 250 C. but below that at which substantial decomposition occurs, thereby effecting the halogenation of the saturated cycloaliphatic hydrocarbons organic compounds while inhibiting the halogenation of the unsaturated compounds, and separately recovering the saturated halides thus produced.

10. In a process for the halogenation of saturated organic compounds of the group consisting of aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and partially halogenated aliphatic and cycloaliphatic' hydrocarbons containing at iecting the mixture thus obtained to the action 01' a halogen selected from the group consisting of chlorine, bromine and iodine in a vapor state and at an elevated temperature above that normally employed in reactions involving halogen addition to oleflns, whereby the halo-substitution of the saturated organic compound is effected at a temperature below that which would be-necessary for the same degree of halo-substitution of the oxygen-contaminated saturated organic compound in the absence of said unsaturated organic compound.

ll. In a process for the 'halogenation of saturated organic compounds of the group consisting of aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and partially halogenated aliphatic and cycloaiiphatic hydrocarbons containing at least one-hydrogen atom linked to a carbon atom which are contaminated by free oxygen, the step of subjecting the oxygen-contaminated saturated organic compoimd, in the vapor phase and at a temperature above 250 C. but below that at which substantial decomposition of the carbon structure occurs to the action of a halogen selected from the group consisting of chlorine. bromine and iodine in the deliberate presence of an unsaturated organic compound selected from the group consisting of aliphatic and alicyciic olefins and of their products of halo-substitution, thereby enacting the halo-substitutionot' I said saturated organic compound.

12. In a process for the halogenation of saturated organic compounds of the group consisting of aliphatic hydrocarbons, cycloaliphatic hydrocarbons, and partially halogenated aliphatic and cycloaliphatic hydrocarbons containing at least one hydrogen atom linked to a carbon atom which are contaminated by free oxygen, the step of reacting the oxygen-contaminated saturated organic compound in a vapor state with a halogen selected from the group consisting of chlorine, bromine and iodine, in the deliberate presence of an unsaturated organic compound selected from the group consisting of aliphatic and alicyclic olefins and of their products of halo-substitution, said reaction being effected at an elevated temperature above that normally employed in reactions involving halogen addi-- tion into oleflns.

' WIILIAM E. VAUGHAN.

FREDERICK F. RUST.

.Patent No. 2,281.,1483.

CERTIFICATE 'oFboRREqTIoN. i f may 9 4 WILLIAM E. VAUGHAN, ET AL.

. It. is hereby: certified that e'rror appears the printed specification of the-above numbered intent requiring correction as follows; Page 5, secondco1tu nn, li.ne l5,"ciaimh., for "about" read above ahdthat the said Ltters' Patent should be re ad with this correction therein that the same may conform to the record offthe c'aso in the Patent Office.

Signed-and. aealedthis hth dgy of August, A. D. 1911.2

. Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

